#include <iostream>

using namespace std;

long fun(long j)
{
    long out = 0;
    do{
        out += j%10;
        j = j/10;
    }while(j/10>0);
    out += j;
    return out;
}

void fun2(long orig, long suc)
{
    long nas = 0;
    for(int i = 11; ;i++)
    {
        nas = 0;
        nas = i * orig;
        if(fun(nas) == suc)
        {
            cout << i << endl;
            break;
        }
    }
}

int main()
{
  long i;
    while(cin >> i)
    {
        if(i == 0)
            break;
        fun2(i,fun(i));
    }
  return 0;
}